Ew. One firm 'no, stop getting in my space' type of comment. Then inform lecturer/ course head or similar.
Please don't make yourself vulnerable by giving him very personal info because you somehow need to excuse your perfectly reasonable request for someone to respect your boundaries, body, space and right to learn. No excuse necessary. And to give this man, who is already trampling I've your boundaries, even a snippet of deeply private information about you... Well, that means you're offering yourself up to him to continue or even step it up. Don't mean that in a victim blamey way, but a transactional analysis of the way women end up so stuck in these types of situations, by men who are good at manipulating boundaries to impose their own levels of intimacy on you, irrespective of your needs and wants. You are not a human sacrifice so don't give him anything more intimate to use - and he's not an exception to any rules of respect for others. No matter what his 'schtick' that he's using to invade your space, and divert attention into him even in the middle of lectures!
Would it be mean to say "sorry I'm trying to learn now" and then follow it up with a 'ooh, is this why you failed last year?
And yes. Mean. Stooping to his level. But booo, what a shame you want to be the bigger person in this :)
I bet this inappropriate behaviour was why he failed really. Who tries to divert attention from a lecturer, like he can't quite grasp why he's in that room at that time. To bloody learn you idiot! Grrrr.
Someone with this little respect for other people's boundaries would be absolutely terrifying as a doctor, or nurse. I can imagine him looming over a patient and both upsetting them terribly, and making dangerous medical mistakes.
The kind which happen when the HCP believes they don't have to listen to anyone but their own dulcet tones, so ignores the patient who is trying to tell him they're on heart medication etc.
And as for the exuberant smashing of boundaries and no respect for others... Imagine you are very ill, tubes stick in you, machines beeping. You are scared and in pain. You have nothing but a gown on, and it's come apart at the back so you're completely vulnerable. Perhaps this HCP has just ripped back the curtains and you're not even in bed, you're on a commode. Or you can't see him because someone's put your glasses just out of reach... The ginormous power imbalance is there already. So just imagine if he starts touching you on the shoulder, the hand, patting your knee as he sits on your bed. Or getting visibly bored as you finish speaking to someone else like a nurse about medication etc. And he starts twirling his hair or sighing or grabbing a chart and ostentatiously rustling pages to get all eyes back on him, the God of... Whatever type of medic.
Utterly horrendous.